diff --git a/Tests/test_file_gif.py b/Tests/test_file_gif.py index 13eb06897b9..00bf582fafb 100644 --- a/Tests/test_file_gif.py +++ b/Tests/test_file_gif.py @@ -957,3 +957,13 @@ def test_missing_background(): with Image.open("Tests/images/missing_background.gif") as im: im.seek(1) assert_image_equal_tofile(im, "Tests/images/missing_background_first_frame.png") + + +def test_saving_rgba(tmp_path): + out = str(tmp_path / "temp.gif") + with Image.open("Tests/images/transparent.png") as im: + im.save(out) + + with Image.open(out) as reloaded: + reloaded_rgba = reloaded.convert("RGBA") + assert reloaded_rgba.load()[0, 0][3] == 0 diff --git a/src/PIL/GifImagePlugin.py b/src/PIL/GifImagePlugin.py index 55b09abec54..8c2180bc115 100644 --- a/src/PIL/GifImagePlugin.py +++ b/src/PIL/GifImagePlugin.py @@ -425,7 +425,13 @@ def _normalize_mode(im, initial_call=False): palette_size = 256 if im.palette: palette_size = len(im.palette.getdata()[1]) // 3 - return im.convert("P", palette=Image.ADAPTIVE, colors=palette_size) + im = im.convert("P", palette=Image.ADAPTIVE, colors=palette_size) + if im.palette.mode == "RGBA": + for rgba in im.palette.colors.keys(): + if rgba[3] == 0: + im.info["transparency"] = im.palette.colors[rgba] + break + return im else: return im.convert("P") return im.convert("L")